Year | Value | 2021 | 40,310 | 2020 | 39,710 | 2019 | 39,220 | 2018 | 38,630 | 2017 | 38,369.688 | 2016 | 37,337.654 | 2015 | 37,898.771 | 2014 | 37,151.9 | 2013 | 37,309.7 | 2012 | 36,960 | 2011 | 36,200 | 2010 | 36,710 | 2009 | 36,890 | 2008 | 35,420 | 2007 | 35,380 | 2006 | 35,330 | 2005 | 35,230 | 2004 | 34,780 | 2003 | 34,090 | 2002 | 34,240 | 2001 | 33,380 | 2000 | 32,910 | 1999 | 34,830 | 1998 | 32,596.2 | 1997 | 32,449.2 | 1996 | 31,764.6 | 1995 | 32,830 | 1994 | 30,126.6 | 1993 | 30,151.8 | 1992 | 29,962.8 | 1991 | 26,430 | 1990 | 26,480 | 1989 | 25,710 | 1988 | 25,810 | 1987 | 25,470 | 1986 | 25,670 | 1985 | 24,970 | 1984 | 24,582.6 | 1983 | 24,347.4 | 1982 | 24,452.4 | 1981 | 24,680 | 1980 | 24,450 | 1979 | 24,470 | 1978 | 25,400 | 1977 | 26,350 | 1976 | 27,300 | 1975 | 28,250 | 1974 | 28,430 | 1973 | 28,550 | 1972 | 28,550 | 1971 | 28,520 | 1970 | 28,430 | 1969 | 28,350 | 1968 | 28,010 | 1967 | 28,010 | 1966 | 27,800 | 1965 | 26,720 | 1964 | 25,060 | 1963 | 24,900 | 1962 | 25,050 | 1961 | 25,680 |
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